Identification of potential tobramycin-resistant mutagenesis of Escherichia coli strains after spaceflight.

Aim: This study aimed to explore potential tobramycin-resistant mutagenesis of Escherichia coli strains after spaceflight.

Materials & Methods: A spaceflight-induced mutagenesis of multidrug resistant E. coli strain (T1_13) on the outer space for 64 days (ST5), and a ground laboratory with the same conditions (GT5) were conducted. Both whole-genome sequencing and RNA-sequencing were performed.

Results: A total of 75 single nucleotide polymorphisms and 20 InDels were found to be associated with the resistance mechanism. Compared with T1_13, 1242 genes were differentially expressed in more than 20 of 38 tobramycin-resistant E. coli isolates while not in GT5. Function annotation of these single nucleotide polymorphisms/InDels related genes and differentially expressed genes was performed.

Conclusion: This study provided clues for potential tobramycin-resistant spaceflight-induced mutagenesis of E. coli.